Foreign diplomats stationed in the United States are eligible to receive subsidized healthcare benefits as part of the Affordable Care Act (ACA), prompting concern on Capitol Hill over the Obama administration’s inability to explain the loophole.

Two leading Republicans are calling on the IRS to reveal exactly how many foreign diplomats have enrolled in Obamacare and the total cost of benefits they may have received courtesy of U.S. taxpayers.

“Many Americans would be surprised to learn that their tax dollars may be subsidizing health coverage for foreign diplomats,” House Foreign Affairs Committee Chairman Ed Royce (R., Calif.) and House Ways and Means Committee Chairman David Camp (R., Mich.) wrote in a joint letter sent this week to the IRS.

The letter comes after repeated attempts by the lawmakers to investigate the eligibility loophole and obtain further information about any Obamacare subsidies given to foreign diplomats, who operate in the United States as non-immigrants and non-citizens.

“The Committees on Foreign Affairs and Ways and Means are investigating the extent to which these diplomats receive taxpayer-subsidized premium tax credits and cost-sharing subsidies under the Affordable Care Act,” the lawmakers wrote.

At issue is the administration’s ongoing failure to reveal to Congress how many foreign diplomats are cashing in on the healthcare benefits and what the cost to the U.S. taxpayer has been, according to congressional sources working on the issue.

Both the State Department and Department of Heath and Human Services (HHS) have been unable to produce this information because they do not actually track the data, sources told the Washington Free Beacon.

The lawmakers are now asking the IRS for the information due to its jurisdiction over administering the healthcare tax credits.

When contacted for comment about the letter, an IRS spokesman told the Free Beacon that officials had received the request for information and would respond at some point in the future.

The IRS official declined to answer questions seeking more information about any such loophole and would not comment on record about it.

“We fully support the ability of foreign diplomats to purchase health care coverage in the United States,” wrote Royce and Camp. “We do not, however, believe that American taxpayers should subsidize these services.”

The administration has advertised these benefits in the past, according to the lawmakers.

“The State Department has gone so far as to advertise to Foreign Missions, Permanent Missions to the United Nations, and the United Nations Secretariat that health care exchanges and ‘the benefits of the United States Affordable Care Act are available’ to them,” the letter states.

HHS also has confirmed that a foreign diplomat could be eligible for “a premium tax credit” and “cost-sharing reductions” under Obamacare.

The lawmakers are asking the IRS to reveal the total number of foreign diplomats who have signed up for any such benefits and “the total cost” associated with them.

The letter comes after “repeated requests” from the Foreign Affairs Committee for similar information.

Initial questions about the loophole were sparked by the 2013 arrest of 25 Russian diplomats accused of illegally trying to obtain Medicaid benefits.